Oklahoma is third in both human polls and first in the BCS standings, but Oklahoma State and Missouri are the lowest-ranked unbeaten teams in the nation. The Cowboys and Tigers are ranked behind six one-loss teams in the coaches' poll, and neither is in the top 10 of the BCS standings.

Perhaps the slights can be explained by less-than-challenging schedules. Or maybe it's a matter of close games against opponents from perceived inferior conferences. Or it could just a matter of their own histories -- neither the Cowboys nor the Tigers have won a Big 12 championship.

Both can answer any doubters on Saturday in home games against higher-profile and higher-ranked opponents. Missouri faces Oklahoma, while Oklahoma State takes on Nebraska.

Some might doubt Missouri because the Tigers struggled to a 27-24 win over San Diego State. But a similar struggle isn't held against Oklahoma, which held on for a three-point win over Air Force, which last week lost to San Diego State.

But Oklahoma has proven itself over time and Missouri hasn't. And the Tigers sure haven't proved anything when facing Oklahoma. Missouri has lost seven in row to the Sooners, including blowout losses in the 2007 and '08 Big 12 championship games.

Missouri coach Gary Pinkel, rightfully so, hasn't brought up those losses to this team this week.

"All our players are very aware, No. 1, how good Oklahoma is," Pinkel said. "No. 2, they know it's a big game. They're very aware of that. Talking about that will not help us play better. What will help well is focusing on what got us to this point so far."

That has been a sharp passing game featuring QB Blaine Gabbert and WR T.J. Moe. But Missouri always throws well. This season, the Tigers are playing sound defense, too. They've allowed the second-fewest points in the country, have held five of six opponents to less than 20 points and are among the nation's leaders in sacks. Saturday, they figure to get a boost with the possible return of star DE Aldon Smith from a leg injury.

Some think this could be the best defense Pinkel has had in 10 years in Columbia.

"I don't know if it's the best defense. That will be evaluated at the end of the year," he said. "We're playing some consistent defense. And we're probably playing as good a team defense as ever. We don't have a lot of great, great players on defense, but we have a lot of good ones. We've played good defense, and that's given us a chance for consistency."

Oklahoma State hasn't played great defense: The Cowboys have allowed at least 28 points to four of their opponents. But they've more than compensated with an explosive offense that averages 535 yards and 49.5 points to rank second in the nation in both categories. They've done that with first-year starting quarterback Brandon Weeden, sophomore receiver Justin Blackmon and a rebuilt offensive line.

"I think for me to say I wouldn't be surprised at all by the performance we're getting out of some of our younger players would be misleading," Oklahoma State coach Mike Gundy said. "I felt like we had a chance to compete and have an opportunity to win our games, but you never really know when you have a new quarterback, four new starters in the offensive line and so many role players on defense that are true freshmen."

Still, some doubt the Cowboys because they struggled to a 41-38 victory over Troy of the Sun Belt Conference and posted a sloppy 38-35 victory over error-prone Texas A&M thanks to a last-play field goal.

While the Cowboys can add further validation against Nebraska, the Huskers will be looking for redemption after last week's loss to Texas.

"Hopefully some of the younger players have learned what it takes to compete in conference play and big games," Gundy said. "Nebraska is a really good football team. A week or 10 days ago, most people across the country would think they'd have a chance to compete for the national championship."

If Oklahoma State and Missouri can post victories, maybe doubters will start believing they have a chance to compete for it, too.

Best matchup: Oklahoma State WR Justin Blackmon vs. Nebraska CB Prince Amukamara. Amukamara is the best pass defender on the nation's best pass defense. So it stands to reason that Amukamara frequently will be matched up on Blackmon, a sophomore who leads the nation with 159.1 receiving yards per game and 12 touchdown receptions. Blackmon hasn't been held to fewer than six catches or 127 receiving yards. But he hasn't faced a cornerback as good as Amukamara, either. Oklahoma State needs to be productive in the passing game to beat Nebraska.

Player on the spot: Baylor LB Chris Francis. Baylor's run defense has been only so-so this season and needs to have a solid performance against Kansas State. That puts a lot of pressure on Bears middle 'backer Francis, who is second on the team in tackles, to help slow Kansas State RB Daniel Thomas. The Wildcats' passing game won't scare anybody, but Thomas does. Francis must have a strong game if Baylor has any chance at containing Thomas.

Numbers game: Maybe Texas A&M has stage fright. The Aggies have lost 12 consecutive televised games since beating Iowa State in 2008. On Saturday the Aggies play Kansas. On Fox Sports Net.

What they're saying

"You look back, and I don't know if it was the right thing to do. If you look back, Taylor wasn't the only problem. We were just looking for a spark. It was a tough situation as a young guy, and like I said, you live and learn as a head coach. You don't know if that was the right decision to make, but it was the decision that was made and you move forward." -- Nebraska coach Bo Pelini, second-guessing himself for benching QB Taylor Martinez in the second half of last week's loss to Texas

"We're just trying for wins. Sometime at the end of the season we'll add them up, but right now we're just trying to be a good football team." -- Baylor coach Art Briles, whose team can become bowl eligible for the first time since 1994 with a victory over Kansas State on Saturday

"What's happened in the past is in the past. And now here is a new season for us, and we have to just continue to move on." -- Kansas coach Turner Gill, looking for the Jayhawks (2-4) to improve their showing in the second half of the season

Etc.: Baylor has scored 114 points in three Big 12 games. That's more than the Bears scored in all eight conference games last season. ... Colorado RB Rodney Stewart recorded the 11th 100-yard rushing performance of his career last week against Baylor. He also became the 16th Colorado player to post 2,000 career rushing yards. ... Iowa State will face its third straight ranked opponent and fourth of the season when it plays Texas on Saturday. ... Iowa State LB A.J. Klein is having a strong year. He leads the team with 49 tackles and three interceptions. He has returned the interceptions for 100 yards. ... Kansas P Alonso Rojas has had a punt of 50 yards or more in every game. ... Kansas State senior DB Stephen Harris set a school record in the Wildcats' win over Kansas by returning a fumble 85 yards for a touchdown. It also was the third-longest fumble return in Big 12 history. ... Kansas State RB Daniel Thomas ranks eighth in the nation with a 130.3 yards-per-game average. He's seventh among running backs. ... Missouri will host "ESPN GameDay" for the first time. The Tigers are seeking their first 7-0 start since 1960. ... Nebraska is ranked No. 1 in passing defense and No. 4 in total defense. The Huskers have held 13 consecutive opponents to 21 or fewer points. ... Oklahoma WR Ryan Broyles is coming off a season-high 182 receiving yards against Iowa State. He has had at least 100 receiving yards in five of OU's six games. ... Oklahoma State WR Josh Cooper is expected to be at full strength and completely recovered from a head injury endured two weeks ago. ... Oklahoma State RB Kendall Hunter needs 170 rushing yards to reach the 1,000-yard mark. WR Justin Blackmon needs 45 receiving yards to reach 1,000. ... Texas football operations director Cleve Bryant has taken a leave of absence while the university investigates allegations made against him. The nature of the allegations has not been revealed, but they were made by a female part-time employee in the athletic department. ... Texas A&M has lost its past 10 games when rushing for 190 or fewer yards; the Aggies have won their past nine when rushing for more than 190 yards. ... A&M G Evan Eike has a sprained ankle and his status for this week's game is questionable. If Eike can't play, T Brian Thomas will shift to guard. That would leave A&M starting true freshmen Luke Joeckel and Jake Matthews at the tackle spots. ... Texas Tech LB Bront Bird hopes to build on last week's game in which he had 14 tackles and an interception. ... Missouri's Michael Egnew leads all tight ends in the country with 49 receptions.

Olin Buchanan is the senior college football writer for Rivals.com. He can be reached at olin@rivals.com.